Lost in Thoughts All Alone (if～ひとり思う～ if ~hitori omou~ lit. if ~one's thoughts~) is Azura's song in Fire Emblem Fates and the main theme of the game. The Japanese version is sung by Renka, while the English version is sung by Rena Strober.
The Japanese version of the song received an album release shortly after the release of Fates itself, and also received a limited edition release. The album contains two versions of Lost in Thoughts All Alone itself as well as two other songs by Renka, and the limited edition adds a DVD with two music videos for Lost in Thoughts All Alone, one of which is Fire Emblem-themed.
This song is performed several times in Fates. Azura first sings the first stanza of the song by a lake during the opening cutscene and when first meeting the Avatar in Chapter 4.
The original version first heard during the first trailer of Fates is by Azura during the Hoshido route, causing strong discomfort to King Garon. She sings a much faster, different tempo, and lower key version of the song during the Nohr route, causing King Garon pain severe enough to make his eyes roll back instead. Her dance during the different versions of the song are also different. Her Hoshido route dance is slower and graceful while her Nohr dance is faster and passionate.
Parts of the lyrics are also heard during each final battle.
Azura's son Shigure also learned to sing the song and often sang it with Azura as he grew up. In his supports with Azura, he has trouble hitting the right notes due to his voice changing.
In Revelation, the Avatar and Azura discuss its possible origins: while the true origin was lost in time by that point, Azura speculates that it acted as a cry for help from Anankos for those who understood the meaning of the lyrics and to free him from his madness with death.
In the Record Hall's ancient texts, the three separate verses of the song are listed as the prophecies of Sky, Land and Below and are said to be the three prophetic songs meant to save Anankos when he descends into madness. The Prophecy of Sky contains the Birthright verse, and the verse appears in the End of All (Sky). The Prophecies of Land and Below also correspond to End of All (Land) and End of All (Below) respectively. The Sky version is sung in the Birthright Endgame, the land version is sung in the Conquest Endgame, and the Below version is sung in the Revelation Endgame.
The song's origin is finally revealed in Hidden Truths, where Anankos reveals himself as its the creator. It was meant to be used by a Songstress in conjunction with the pendant made from a piece of his Dragonstone to weaken himself. However, it began to lose its effect on him over time and the use of the pendant started killing the Songstresses. The song itself is meant to be sung from Anankos' perspective about his child, the Avatar. If the song is sung without the pendant, it has no effect aside from being a normal song.
In Heirs of Fate, it is revealed there is a fourth verse of the song that is too powerful for even Azura to sing, which both the first King of Valla and Shigure can at the cost of vanishing. Azura teaches Shigure the verse to save the world where they failed to defeat Anankos after going to Valla.